JP2008507329A - System and method for real-time tracking of targets in radiation therapy and other medical applications - Google Patents

Abstract

Systems and methods for tracking a target in real time for radiation therapy and other applications are disclosed. In one embodiment, the method collects position information of a marker embedded at a position associated with the target within the patient at time t _n , and the position of the target based on the position information collected at time t _n . Providing an objective output indicative of The objective output is supplied to the memory device, the user interface, and / or the radiation irradiator within 1 to 2 seconds from the time t _n when the position information is collected. This embodiment of the method may further include providing an objective output with a period of 10-200 ms, at least during a portion of the therapeutic procedure. For example, the method includes generating a beam of ionizing radiation and directing the beam to the machine isocenter, and collecting and delivering procedures every 10-200 milliseconds while irradiating the patient with the ionizing radiation beam. Can be further included.

Description

The present invention relates generally to radiation therapy systems, and more particularly to systems and methods for accurately positioning and tracking a target in real time to teach and evaluate radiation therapy. The present invention, however, is useful in other medical applications.
This application claims the benefit of US Provisional Application No. 60 / 610,509, filed September 16, 2004, and US Provisional Application No. 60 / 590,894, filed July 23, 2004. Yes, both of these patent documents are hereby incorporated by reference in their entirety.

  Radiation therapy has become an important and highly successful treatment method for treating prostate cancer, lung cancer, brain tumors and many other types of local cancer. Radiotherapy procedures generally include (a) a planning process for determining radiation parameters (eg, dose, shape, etc.), (b) a patient positioning process for placing the target in a desired position relative to the radiation beam, ( c) a radiation period for irradiating the gun, and (d) a verification process for evaluating the effect of the radiation period. Many radiotherapy treatments require several irradiation periods (ie, irradiation fractions) over a period of about 5 to 45 days.

  In order to improve the treatment of local cancer by radiation therapy, it is generally desirable to increase the radiation dose, as higher doses are more effective at eradicating most cancers. However, increasing the radiation dose also increases the likelihood of complications in healthy tissue. Thus, the effectiveness of radiation therapy depends on both the total dose of radiation delivered to the tumor and the dose delivered to normal tissue adjacent to the tumor. In order to protect normal tissue adjacent to the tumor, radiation should be prescribed within a strict treatment margin around the target so that only a small portion of healthy tissue is irradiated. For example, the treatment margin for prostate cancer should be selected to avoid irradiation of rectal, bladder, and bulbar urethral tissues. Similarly, the treatment margin for lung cancer should be selected to avoid irradiating healthy lung tissue or other tissues. Therefore, it is desirable not only to increase the radiation dose irradiated to the tumor, but also to reduce the irradiation to healthy tissue.

  One difficulty with radiation therapy is that the target often moves within the patient's body during or between periods of radiation. For example, the prostate moves in the patient's body during radiation exposure due to respiratory motion and / or filling / excretion (eg, full or empty bladder). Lung tumors also move during irradiation due to respiratory motion and cardiac function (eg, beating and vasoconstriction / inflation). In order to compensate for such movement, the treatment margin is generally larger than desired so that the tumor does not go out of the treatment volume. This is not a desirable solution because a larger treatment margin may irradiate a larger volume of normal tissue.

  Another challenge of radiation therapy is to accurately align the tumor with the radiation beam. In the current positioning process, it is common to align the external reference marking on the patient with the visual alignment guide of the radiation delivery device. As an example, a tumor is initially identified in a patient using an imaging system (eg, X-ray computed tomography (CT), magnetic resonance imaging (MRI), or ultrasound device). Next, the approximate location of the tumor relative to two or more alignment points outside the patient's body is determined. During positioning, the external mark is aligned with the reference coordinate system of the radiation delivery device in order to place the treatment target within the patient at the beam isocenter of the radiation beam (also referred to herein as the machine isocenter). . The normal positioning process using external marks is generally inadequate because the target may move relative to the external marker between the patient treatment planning process and the treatment period and / or during the treatment period. . Accordingly, in order to place the target at the machine isocenter, the target position may be removed from the machine isocenter even when the external mark is at a predetermined position. Since any initial misalignment between the target and the radiation beam is likely to result in irradiation of normal tissue, it is desirable to reduce or eliminate such an offset. In addition, if the target moves during treatment due to respiration, organ fullness, or cardiac conditions, any initial misalignment tends to further exacerbate normal tissue. Thus, daily and instantaneous instantaneous target motion changes pose a significant challenge with respect to increasing the dose of radiation applied to the patient.

  Normal positioning and treatment processes using external marks also require a straight line of sight between the mark and the detector. This requirement renders these systems useless for implanted markers or markers in other conditions within the patient (ie, off the line of sight of the detector and / or light source). Thus, conventional optical tracking systems have many limitations that limit their usefulness in medical applications.

  In the accompanying drawings, the same reference number represents a similar element or component. The sizes and relative positions of elements in the drawings are not necessarily drawn to scale. For example, the shapes and angles of the various elements are not drawn to scale, and some of these elements are arbitrarily enlarged and arranged to improve viewability. Further, the particular shape in which the element is drawn is not intended to convey any information about the actual shape of the particular element, but is simply selected for ease of recognition in the drawings. .

  In the following description, certain specific details are set forth in order to provide a thorough understanding of various embodiments of the invention. However, one of ordinary skill in the art appreciates that the invention can be practiced without one or more of these specific details, or with other methods, components, elements, and the like. Will. In other instances, well-known structures associated with the target positioning and tracking system are not shown or described in detail to avoid unnecessarily obscuring the description of the embodiments of the invention.

  Unless the context requires change, throughout this specification and the appended claims, the word “comprising” and its derivatives, such as “including” and “including,” include “ It should be interpreted in an open sense that includes the meaning of “not done”.

Throughout this specification, reference to “an embodiment” or “an embodiment” refers to a particular feature, structure, or characteristic described in connection with that embodiment, that is at least one implementation of the invention. Means included in the form. Thus, the phrases “in one embodiment” or “in one embodiment” appearing in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
The headings provided herein are for convenience only and do not explain the scope or spirit of the claimed invention.

A. Overview FIGS. 1-24 show a system and several components for positioning, tracking, and monitoring a target in a patient in real time according to an embodiment of the present invention. The system and components direct and control radiation therapy to treat the target more effectively. Some embodiments of the system described below with reference to FIGS. 1-24 treat targets in the lung, prostate, head, neck, chest, and other parts of the body in accordance with aspects of the present invention. Can be used for In addition, the markers and positioning systems shown in FIGS. 1-24 can also be used for surgical or other medical applications. Like reference numbers represent like components and features throughout the various figures.

  Some embodiments of the present invention are directed to a method for tracking a target, i.e., a method for measuring the position and / or rotation of a target within a patient in a medical application in substantially real time. One embodiment of the method includes collecting position data for markers that are substantially fixed relative to the target. This embodiment further includes determining the position of the marker in an external reference coordinate system (ie, a reference coordinate system outside the patient) and producing an objective output in the external reference coordinate system that corresponds to the position of the marker. . The objective output is given repeatedly at a frequency / cycle that properly tracks the target position in real time within the scope of clinically acceptable tracking errors. Thus, the method of tracking the target allows the target to be accurately tracked throughout a diagnosis, planning, treatment or other type of medical process. In many specific applications, the objective output is provided within a reasonably short waiting time after location data collection and at a sufficiently high frequency to use location data for such treatment processes.

Another particular embodiment is a method of treating a target within a patient using an ionizing radiation beam, wherein the position information of a marker embedded at a location associated with the target within the patient is collected at time t _n . And providing an objective output indicating the position of the target based on the position information collected at time t _n . The objective output is supplied to the memory device, the user interface, and / or the radiation irradiator within 2 seconds from the time t _n when the position information is collected. This embodiment of the method may further include providing an objective output with a period of 2 seconds or less during at least a portion of the treatment process. For example, the method further includes the steps of generating an ionizing radiation beam, directing the beam to the machine isocenter, and collecting and delivering every 10-200 ms when the patient is irradiated with the ionizing radiation beam. Continuously repeating steps.

  Another embodiment of a method for tracking a target in a patient body includes obtaining position information of a marker placed at a position associated with the target in the patient body, and a marker in an external reference coordinate system based on the position information. Determining the position of. This embodiment includes (a) a frequency sufficiently high so that the pose of display of the target position in the user interface is not easily recognizable by humans, and (b) acquisition of marker position information and at least substantially The method further includes providing an objective output to the user interface indicating the position of the target with a short waiting time to be simultaneous.

  Another embodiment of the invention is directed to a method of treating a patient target using an ionizing radiation beam by generating an ionizing radiation beam and directing the beam relative to the target. The method further includes collecting positional information of the marker implanted at a location associated with the target within the patient while directing the beam to the beam isocenter. In addition, the method includes providing an objective output indicating the position of the target relative to the beam isocenter based on the collected position information. The method can further include correlating the objective power with the parameters of the beam and controlling the beam based on the objective power. For example, the beam can be gated so that the patient is illuminated only when the target is within the desired illumination zone. In addition, while irradiating the patient, the patient can be automatically moved by objective output to provide real-time dynamic control that maintains the target in the desired position relative to the beam isocenter or beam The shape can be automatically adapted.

  In this section, various embodiments of the present invention are described to provide specific details in order to fully understand and practice the description of these embodiments. Those skilled in the art will appreciate, however, that the invention can be practiced without some of these details, or that additional details can be added to the invention. Where the context permits, singular or plural terms may include plural or singular terms, respectively. Further, unless the word “or” is specifically limited to mean only a single item that refers to at least two items and excludes other items, the use of “or” in those lists is It should be construed to include (a) any single item in the list, (b) all items in the list, or (c) any combination of items in the list. In addition, the term “comprising” is meant to include at least the listed features throughout, so that optionally any number of the same features and / or other types of features or components are not excluded.

B. Radiotherapy system with real-time tracking system FIGS. 1 and 2 show guided radiation therapy on a target 2 (eg, a tumor) in the lung 4, prostate, breast, head, neck or other part of a patient 6. Various aspects of a radiation therapy system 1 for application are shown. The radiation therapy system 1 includes a positioning system 10 and a radiation irradiation device 20. The positioning system 10 tracks and tracks the actual position of the target 2 in real time during treatment planning, patient positioning and / or when ionizing radiation is being applied to the target from the radiation delivery device. Is a unit. Thus, while the target 2 may move within the patient for breathing, organ filling / excretion, cardiac function or other internal movement, as described above, the positioning system 10 may be used as an external reference for the irradiation device. The movement of the target with respect to the coordinate system or other external reference coordinate system outside the patient's body is accurately tracked so that the radiation is accurately delivered within a small limited area around the target. The positioning system 10 can also monitor marker placement and trajectory to provide an early indication of tumor change without the use of ionizing radiation. In addition, the positioning system 10 continuously tracks the target and provides objective data (eg, three-dimensional coordinates in an absolute reference coordinate system) to memory devices, user interfaces, linear accelerators, and / or other devices. To do. Although the system 1 is described below in the context of guided radiation therapy to treat a tumor or other target within a patient's lungs, the system can be used to transfer the prostate or other target within the patient to other It can be used to track and monitor for treatment and / or diagnosis.

  The radiation source of the illustrated embodiment is an ionizing radiation device 20 (ie, a linear accelerator). A suitable linear accelerator is available from Varian Medical Systems, Inc., Palo Alto, California. Siemens Medical Systems, Inc., Iserin, NJ, USA. Elekta Instruments, Inc., Iserin, New Jersey, USA. Or manufactured by Mitsubishi Electric Corporation of Japan. These linear accelerators perform conventional single or multiple field radiation therapy, 3D conformal radiation therapy (3D CRT), intensity modulated radiation therapy (IMRT), stereotaxic radiation therapy, and tomotherapy be able to. The radiation source 20 directs a gated, contoured or shaped beam of ionizing radiation 21 from a movable gantry 22 to a range or volume at a known position in the external absolute reference coordinate system associated with the radiation source 20. Can be irradiated. The point or volume to which the ionizing radiation beam 21 is directed is called the machine isocenter.

  The tracking system includes a positioning system 10 and one or more markers 40. The positioning system 10 determines the actual position of the marker 40 in the three-dimensional reference coordinate system, and the marker 40 is normally implanted in the body of the patient 6. In the embodiment shown in FIGS. 1 and 2, more specifically, the three markers, individually identified as markers 40a-40c, are located in or near the target 2 in or near the lung 4 of the patient 6. It is embedded in the vicinity. In other applications, a single marker, two markers, or more than three markers can be used depending on the particular application. For example, two markers are desirable because the position of the target can be accurately determined, and any relative displacement over time between the two markers is not a marker within the patient. This is because it can be used to monitor movement. The marker 40 is positioned relative to the target 2 so that it is at least substantially fixed relative to the target 2 (eg, the marker moves directly with the target or moves at least directly in proportion to the movement of the target). It is desirable. The relative position between the markers 40, and the relative position between the target isocenter T of the target 2 and the marker 40 is determined during the treatment planning stage before the patient is placed on the table during the CT scanner or other Can be determined with respect to an external reference coordinate system defined by the type of imaging system. In certain embodiments of the system 1 shown in FIGS. 1 and 2, to reduce side effects on adjacent healthy tissue and to ensure that the desired dose is applied to the target, During the positioning process and while illuminating the patient, the positioning system 10 tracks the three-dimensional coordinates of the marker 40 relative to the absolute external reference coordinate system in real time.

C. General Aspects of Marker and Positioning System FIG. 3 is a schematic diagram illustrating the operation of one embodiment of positioning system 10 and markers 40a-40c for treating a tumor or other target in a patient. The positioning system 10 and the markers 40a-40c are used to determine the position of the target 2 (FIGS. 1 and 2) before, during and after the irradiation period. More specifically, the positioning system 10 determines the position of the markers 40a-40c in real time during positioning, treatment, deployment, simulation, surgery, and / or other medical processes, and is objective. Target position data is provided to a memory, user interface, linear accelerator, and / or other device. In one embodiment of the positioning system, real time means that the objective coordinate index is (a) a refresh rate that is high enough (ie, frequency) that the poses in the data are not recognizable to humans. And (b) means being provided to the user interface with a sufficiently short latency such that it is at least substantially simultaneous with the measurement of the positioning signal. In other embodiments, real time is defined by a high frequency range and a low latency range for supplying objective data to the radiation delivery device, or in yet other embodiments, real time is , Defined as providing objective data corresponding to the position of the marker (eg, how often to properly track the position of the target in real time, and / or latency substantially simultaneous with the acquisition of the marker position data. In).

1. Positioning System The positioning system 10 includes an excitation source 60 (eg, a pulsed magnetic field generator), a sensor assembly 70, and a controller 80 coupled to both the excitation source 60 and the sensor assembly 70. The excitation source 60 generates excitation energy to excite at least one of the markers 40a-40c (FIG. 1) in the patient 6. The embodiment of the excitation source 60 shown in FIG. 3 generates a pulsed magnetic field of various frequencies. For example, the excitation source 60 excites the first frequency E ₁ to excite the first marker 40a, the second frequency E ₂ to excite the second marker 40b, and the third marker 40c. In addition, the magnetic field can be frequency division multiplexed at the third frequency E ₃ . In response to the excitation energy, markers 40a-40c generate position signals L _1-3 at their own response frequency. More specifically, the first marker 40a in response to the excitation energy at the first frequency E _1, the first position signal L ₁ generated in the first frequency, the second marker 40b, the second frequency E _In response to the excitation energy at 2, a second position signal L ₂ is generated at the second frequency, and the third marker 40 c is third at the third frequency in response to the excitation energy at the third frequency E ₃ . generating a position signal L _3. In an alternative embodiment using two markers, the excitation source, generates a magnetic field in the frequency E ₁ and E _2, markers 40a-40b generates a position signal L ₁ and L _2, respectively.

Sensor assembly 70 can include a plurality of coils for detecting position signals L _1-3 from markers 40a-40c. The sensor assembly 70 may be a flat panel having a plurality of coils that are at least substantially coplanar with each other. In other embodiments, sensor assembly 70 may be a non-planar array of coils.

The controller 80 includes hardware, software or other computer operable medium that includes instructions for operating the excitation source 60 to split and multiplex the excitation energy to various frequencies E _1-3 . For example, the controller 80 causes the excitation source 60 to generate excitation energy of the first frequency E ₁ during the first excitation period, and then the controller 80 causes the sensor assembly 70 to be free of the excitation energy of the first frequency E ₁ . For the first detection step of detecting the first position signal L ₁ from the first marker 40a, the excitation energy of the first frequency E ₁ is terminated in the excitation source 60. The controller 80 then causes the excitation source 60 to (a) generate a second excitation energy at the second frequency E ₂ during the second excitation period, and (b) the sensor assembly 70 to generate an excitation energy at the second frequency E ₂ . The excitation energy of the second frequency E ₂ is terminated for a second detection stage in which the second position signal L ₂ from the second marker 40b is detected without the presence of. The controller 80 then performs this operation for the third excitation energy at the third frequency E ₃ so that the third marker 40c transmits the third position signal L ₃ to the sensor assembly 70 during the third detection stage. repeat. Accordingly, the excitation source 60 wirelessly transmits the pump energy to the excitation period in the form of a pulsed magnetic field at the resonant frequency of the marker 40a-40c, marker 40a-40c are located in the detection phase signal L _1-3 the sensor assembly 70 To communicate wirelessly. It will be appreciated that the excitation and detection steps can be repeated to allow the detection signal to be averaged to reduce noise.

Computer operable media in controller 80, or in a separate signal processor, or other computer also includes instructions for determining the absolute position of each of markers 40a-40c in a three-dimensional reference coordinate system. Based on a signal provided by sensor assembly 70 corresponding to the magnitude of each of position signals L _1-3 , controller 80 and / or a separate signal processor may provide each of markers 40a-40c in the three-dimensional reference coordinate system. Calculate absolute coordinates of. The absolute coordinates of each of the markers 40a-40c is objective data that can be used to calculate the coordinates of the target in the reference coordinate system. When multiple markers are used, target rotation can also be calculated.

2. The real-time tracking positioning system 10 and at least one marker 40 are associated with a machine isocenter or another external reference coordinate system outside the patient body during treatment planning, positioning, radiation exposure, and other periods of the radiation treatment process. Allows target 2 to be tracked in real time. In many embodiments, real-time tracking includes collecting marker position data, determining the position of the marker in the external reference coordinate system, and providing an objective output in the external reference coordinate system that corresponds to the marker position. Means supply. The objective output is provided at a frequency that properly tracks the target in real time and / or at a latency (eg, generally within the same time) that is at least substantially simultaneous with the collection of location data.

  For example, some embodiments of real-time tracking include determining the position of the marker and calculating the position of the target relative to the machine isocenter: (a) a pose during display of the target position in the user interface At a sufficiently high frequency that does not interfere with the treatment or easily discernable by humans, and (b) with a sufficiently short waiting time so that it is at least substantially coincident with the measurement of the position signal from the marker, Defined as what to do. Alternatively, real time refers to the positioning system 10 positioning the absolute position and / or target position of each individual marker 40 in a period from 1 ms to 5 seconds, or in many applications from about 10 to 100 ms. It means to calculate with a period, or in some specific applications with a period of about 20 to 50 ms. In applications related to the user interface, for example, the period can be 12.5 ms (ie, a frequency of 80 Hz), 16.667 ms (60 Hz), 20 ms (50 Hz), and / or 50 ms (20 Hz).

  Alternatively, real-time tracking may further include the positioning of the absolute position of the marker 40 and / or the target 2 within the memory device, within a waiting time of 10 ms to 5 seconds from the time when the position signal is transmitted from the marker 40. It can mean supplying to a user interface, linear accelerator or other device. In more specific applications, the positioning system generally provides the position of the marker 40 and / or the target 2 within a waiting time of about 20 to 50 ms. Accordingly, the positioning system 10 can apply more radiation dose to the target and reduce the side effects on healthy tissue, thus increasing the effectiveness of radiation therapy in a manner that is expected to increase Provide real-time tracking to monitor the position of the marker 40 and / or the target 2 with respect to a reference coordinate system.

  Alternatively, real-time tracking can be further defined by tracking errors. The measurement of the position of a moving target suffers from an error due to motion, commonly referred to as tracking error. In accordance with aspects of the present invention, positioning system 10 and at least one marker 40 may track target 2 in real time with tracking error within clinically significant limits with respect to the machine isocenter or other external reference coordinate system. Enable.

  Tracking error is the two limits that any practical measurement system exhibits: (a) the latency between the time the target position is detected and the time when the position measurement is available, and (b) the measurement Due to sampling delay due to periodicity. For example, if the target moves at 5 cm / s and the measurement system has a 200 ms latency, the position measurement will have a 1 cm error. The error in this example is not due to any other measurement error, but only due to the waiting time, simply that the target moved between the time when the position was detected and the time when the position measurement was available. It depends on the facts. If this exemplary measurement system further has a sampling period of 200 ms (ie, a sampling frequency of 5 Hz), the average tracking error is 1.5 cm and the maximum tracking error is increased to 2 cm.

  In order for a real-time tracking system to be useful in medical applications, it is desirable to keep tracking errors within clinically significant limits. For example, in a system that tracks lung tumor motion for radiotherapy, it is desirable to keep tracking errors within 5 mm. When tracking other organs for radiation therapy, the allowable tracking error may be much smaller. According to aspects of the present invention, real-time tracking refers to measurement of target position and / or rotation with tracking error within clinically significant limits.

  The system described here uses one or more markers that serve as registration points to characterize the position, rotation, and movement of the target. According to an aspect of the invention, the marker has a substantially fixed relationship with the target. If the marker does not have a substantially fixed relationship with the target, it will incur another type of tracking error. This generally means that tracking errors are within clinically significant limits, and therefore the marker is fixed to the target so that it can be placed in the tissue or bone that represents the target's typical motion. Or need to embed close enough. For example, with respect to the prostate, the tissue representing the target motion will include tissue that is very close to or adjacent to the prostate. Tissue adjacent to the target including the prostate can include the prostate, the tumor itself, or tissue within a specified radial distance from the target. For the prostate, tracking tissue at a radial distance of 5 cm from the target will give a typical motion that is clinically useful with respect to the motion of the target. With alternative target position tracking, the radial distance can be larger or smaller.

  According to an aspect of the invention, the movement of the marker is a surrogate for the movement of the target. Thus, the markers are arranged to move in direct correlation with the tracked target. Depending on the target being tracked, the direct correlation between the target and the marker will vary. For example, within a long bone, a marker can be placed somewhere along the bone to provide a motion that is directly correlated to the motion of the target within the bone. For example, for soft tissue that moves substantially in response to bone tissue in the head or neck, the marker can be placed in the occlusal block to provide a surrogate motion that directly correlates with the motion of the target. As discussed in detail with respect to soft tissue and above, the markers can be placed in adjacent soft tissue that provides a surrogate with a direct correlation to the target motion.

FIG. 4 is a flow diagram illustrating some aspects and usage of real-time tracking to monitor target position and status. In this embodiment, the integrated method 90 for radiation therapy includes a radiation planning process 91 that determines a plan for delivering radiation to the patient over a number of radiation fractions. Radiation planning process 91 typically includes an imaging stage in which an image of a tumor or other type of target is acquired using x-ray, CT, MRI, or ultrasound imaging. The image is analyzed by a human to measure the relative distance between the markers and the relative position between the target and the marker. FIG. 5A is a display of a CT image showing cross sections of the patient 6, the target 2, and the marker 40, for example. Referring to FIG. 5B, the coordinates (x ₀ , y ₀ , z ₀ ) of the marker 40 in the reference coordinate system R _CT of the CT scanner can be determined by the operator. Tumor coordinates can be determined in the same way to ascertain the offset between the marker and the target.

  The radiation planning process 91 also includes tracking the target using the positioning system 10 (FIG. 3) in an observation area remote from the imaging device. Marker 40 (FIG. 3) tracks to identify changes over time in target morphology (eg, size / shape) and to determine trajectories resulting from movement of the target within the patient (eg, simulation). be able to. For many treatment plans, the computer does not need to provide the user with objective output data regarding the location of the marker or target in real time, rather the data can be recorded in real time. Based on the images obtained during the imaging phase and the additional data obtained by tracking the markers using the positioning system 10 during the simulation process, a treatment plan for irradiating the target with radiation is created.

  The positioning system 10 and the marker 40 allow an automatic patient positioning process for radiation exposure. After creation of the treatment plan, the method 90 places the patient on a movable support such that the target and marker are generally adjacent to the sensor assembly. As described above, the excitation source is activated to excite the marker and the sensor measures the signal intensity from the marker. The computer controller then (a) calculates an objective value for the marker and target position relative to the machine isocenter, and (b) determines an objective offset value between the target position and the machine isocenter. . Referring to FIG. 6, for example, an objective offset value can be provided to a user interface that displays the target's vertical, horizontal, and vertical offsets relative to the machine isocenter. The user interface may additionally or alternatively display the target rotation.

  One aspect of some embodiments of the positioning system 10 is that the position data from the field sensor 70 can be transmitted within the controller 80 or other computer without using an artificial interpretation of the data received by the field sensor 70. By processing, an objective value is provided to a user interface or other device. If the offset value is out of tolerance, the computer will automatically activate the support control system and table against the machine isocenter until the target isocenter matches the machine isocenter. Move the top surface. The computer controller typically supplies the objective output data of the offset in real time as previously defined to the table control system. For example, since the output is supplied to the radiation irradiation apparatus, the waiting time can be short (10-20 ms) at high speed (1-20 ms). If the output data is supplied to the user interface in addition to or instead of the support controller, it can be relatively slow (20-50 ms) and long latency (50-200 ms).

  In one embodiment, the computer controller also determines the marker position and orientation relative to the simulated position and orientation. The location of the simulated marker is selected so that the target is at the machine isocenter when the actual marker is the selected location of the simulated marker. If the marker is not properly positioned and oriented relative to the simulated marker, the support is adjusted as necessary for proper marker position adjustment. This marker positioning adjusts the target appropriately with respect to the six dimensions: X, Y, Z, pitch, yaw, and roll. Thus, the patient is automatically placed in the correct position and rotational position relative to the machine isocenter to accurately deliver radiation therapy to the target.

  Referring back to FIG. 4, the method 90 further includes a radiation period 93. FIG. 7 shows a further advanced aspect of the automatic process in which the positioning system 10 tracks the target during the irradiation period 93 and controls the irradiation apparatus 20 in response to the offset between the target and the machine isocenter. For example, if the target position is outside an acceptable extent or range of displacement from the machine isocenter, the positioning system 10 sends a signal to interrupt radiation exposure or stop the initial operation of the beam. In another embodiment, the positioning system 10 automatically repositions the table top 27 and the patient 6 (as a whole) so that the target isocenter is machine-driven even when the target moves during the radiation period. Try to stay within the desired range of the isocenter. In yet another embodiment, the positioning system 10 sends a signal to activate radiation (eg, gated therapy) only when the target is within the desired range of the machine isocenter. When treating an intrapulmonary target, one embodiment of a gated treatment is to track the target during inspiration / expiration and to the patient for one cycle of inspiration / expiration to breathe his / her breath. And holding the beam 21 when the computer 80 determines that the objective offset value between the target and the machine isocenter is within a desired range. Thus, the positioning system allows dynamic adjustment of the platform 27 and / or the beam 21 in real time when irradiating the patient. This is expected to ensure that the radiation is delivered to the target accurately and without requiring a large treatment margin around the target.

  The positioning system supplies objective data of offset and / or rotation to the linear accelerator and / or patient support in real time as previously defined. For example, as described above with respect to the step of automatically positioning the patient support during the positioning process 92, the positioning system generally provides an objective output at least substantially simultaneously with acquiring the marker position data. And / or supplied to the irradiation apparatus at a frequency sufficient to track the target in real time. The objective output can be supplied, for example, with a short period (1-20 ms) and a short waiting time (10-20 ms), so that a signal for controlling the beam 21 is sent to the radiation irradiation device during the radiation period. Can be supplied at the same time period. In another embodiment of real-time tracking, the objective output can be provided multiple times during the on-beam period (eg, 2, 5, 10 or more times during beam emission). . When terminating or activating a radiation beam or adjusting the beam collimator aim, it is generally desirable to maximize the update rate and minimize latency. Thus, in some embodiments, the positioning system can provide objective output data of the target position and / or marker position with a period of 10 ms or less and a latency of 10 ms or less.

  The method 90 further includes a verification process 94 that compares the real-time objective output data from the radiation exposure period 93 with the parameters of the radiation beam parameters. For example, the target position can be correlated to the beam intensity, beam position, and collimator placement at corresponding time intervals during the radiation exposure period 93. This correlation can be used to determine the amount of radiation to irradiate separate areas within or around the target. This information can also be used to determine the effect of radiation exposure on a specific area of the target by noting changes in target morphology or target trajectory.

  The method 90 may further include a first determination (block 95) that analyzes the data from the validation process 94 to determine whether the treatment is complete. If the treatment is not complete, the method 90 further includes a second decision that analyzes the results of the validation process to determine whether the treatment plan should be modified to compensate for the target change (block 95). )including. If correction is required, the method can proceed by repeating the planning process 90. Conversely, if the treatment plan has yielded adequate results, the method 90 may proceed by repeating the positioning process 92, the irradiation period 93, and the verification process 94 in the next fraction of radiation therapy. it can.

  The positioning system 10 has several features that, individually or in combination, enhance the ability to accurately deliver a high dose of radiation to the target within a tight margin. For example, many embodiments of the positioning system use lead-free markers that are implanted within the patient and substantially secured to the target. Thus, the marker moves directly with the target or in proportion to the movement of the target. As a result, internal movement of the target due to breathing, organ fullness, cardiac function or other factors can be identified and accurately tracked before, during and after the course of treatment. Further, in many aspects of the positioning system 10, non-ionized energy is used to track lead-free markers in an external absolute reference coordinate system in a manner that provides an objective output. In general, the objective output is determined within the computer system without having any artificial interpretation data (eg, images) while the positioning system 10 tracks the target and provides the objective output. This significantly reduces the waiting time between the time when the marker position is detected and the time when the objective output is supplied to the device or user. For example, this allows an objective output corresponding to the target position to be provided at least substantially simultaneously with the collection of marker position data. The system also virtually eliminates user-to-user variability associated with subjective interpretation of data.

D. Specific Embodiments of Markers and Positioning Systems The following specific embodiments of markers, excitation sources, sensors and controllers are additional details for implementing the systems and methods described above with reference to FIGS. give. The inventor generates a marker and (a) a wirelessly transmitted position signal in response to the wirelessly transmitted excitation energy, and (b) is embedded in the lung, prostate, or other part of the patient. Many problems have been overcome to develop a positioning system that accurately determines the position of a marker having a sufficiently small cross-sectional area. A system with these characteristics is: (a) no need for ionizing radiation; (b) no need for a line of sight between the marker and sensor; and (c) an objective of target position and / or rotation. There are several practical advantages including providing measurements. The following specific embodiments are described in sufficient detail so that one of ordinary skill in the art can make and use such a positioning system for radiation therapy associated with a tumor in a patient body, however, The present invention is not limited to the following embodiments of markers, excitation sources, sensor assemblies and / or controllers.

1. Marker FIG. 8A is an isometric view of marker 100 for use with positioning system 10 (FIGS. 1-7). The embodiment of the marker 100 shown in FIG. 8A includes a casing 110 and a magnetic transponder 120 (eg, a resonant circuit) within the casing 110. The casing 110 is a barrier that is configured to be embedded in a patient or inserted into the instrument body. Alternatively, the casing 110 can be configured to adhere to the patient's skin from the outside. The casing 110 may be a generally cylindrical capsule sized to fit within the hole of a small infusion device such as a bronchoscope or a percutaneous transthoracic infusion, but the casing 110 may have other configurations and more It can also be larger or smaller. For example, the casing 110 may have barbs or other mechanisms for securing the casing 110 to soft tissue, or may have an adhesive for attaching the casing 110 to the patient's skin from the outside. A suitable securing mechanism for securing the marker 100 to a patient is disclosed in International Publication No. WO 02/39917 A1, US-designated country, incorporated herein by reference. In one embodiment, the casing 110 includes (a) a capsule or shell 112 having a closed end 114 and an open end 116, and (b) a sealant 118 at the open end 116 of the shell 112. Casing 110 and sealant 118 can be made from plastic, ceramics, glass, or other suitable biocompatible material.

  As described above, the magnetic transponder 120 may include a resonance circuit that wirelessly transmits a position signal in response to the wirelessly transmitted excitation field. In this embodiment, the magnetic transponder 120 includes a coil 122 defined by a plurality of windings of a conductor 124. Many embodiments of the magnetic transponder 120 also include a capacitor 126 coupled to the coil 122. The coil 122 resonates at the selected resonance frequency. The coil 122 can resonate at a resonant frequency that simply uses the parasitic capacitance of the winding without a capacitor, or the resonant frequency can be generated using a combination of the coil 122 and the capacitor 126. Thus, the coil 122 generates an alternating magnetic field at the selected resonant frequency in response to the excitation energy, either by itself or in combination with the capacitor 126. The conductor 124 in the illustrated embodiment may be a hot air or alcohol bonded wire having a gauge of about 45-52. The coil 122 can have a winding number of 800-1000, and the winding is preferably wound into a rigid laminated coil. The magnetic transponder 120 can further include a core 128 composed of a material with suitable magnetic permeability. For example, the core 128 can be a ferromagnetic element composed of ferrite or another material. The magnetic transponder 120 can be fixed to the casing 110 with an adhesive 129.

  The marker 100 also includes an imaging element that improves the quality of the radiographic image so that the marker can be better identified in the radiographic image. The imaging element also has a radiographic profile within the radiographic image such that the marker has a radiographic centroid that at least approximately matches the magnetic centroid of the magnetic transponder 120. As will be explained in more detail below, the radiographic and magnetic centroids do not have to coincide exactly with each other, but rather can be within acceptable limits.

FIG. 8B is a cross-sectional view of the marker 100 taken along line 8B-8B of FIG. 8A illustrating the imaging element 130 according to one embodiment of the present invention. The imaging element 130 shown in FIGS. 8A-8B includes a first contrast element 132 and a second contrast element 134. The first and second contrast elements 132 and 134 are generally relative to the magnetic transponder 120 such that the marker 100 has a radiographic centroid R _c at least substantially coincident with the magnetic centroid M _c of the magnetic transponder 120. Arranged. For example, when the imaging element 130 includes two contrast elements, the contrast elements can be arranged symmetrically with respect to the magnetic transponder 120 and / or with respect to each other. The contrast element can also be identified in the radiograph from the magnetic transponder 120. In such embodiments, the symmetrical arrangement of separate contrast elements improves the ability to accurately determine the radiographic centroid of marker 100 within the radiographic image.

  The first and second contrast elements 132 and 134 shown in FIGS. 8A-8B are continuous rings disposed at opposite ends of the core 128. The first contrast element 132 can be located at or around the first end 136a of the core 128, and the second contrast element 134 can be located at or around the second end 136b of the core 128. be able to. The continuous rings shown in FIGS. 8A-8B have substantially the same diameter and thickness. However, in other embodiments, the first and second contrast elements 132 and 134 can have other configurations and / or be located at other locations relative to the core 128. For example, the first and second contrast elements 132 and 134 can be rings having different diameters and / or thicknesses.

Radiographic centroid of the image generated by the imaging element 130 need not exactly match the magnetically centroid M _c, should rather radiographic centroid magnetically centroid is coincident with the allowable range . For example, the radiographic centroid R _c can be considered at least approximately coincident with the magnetic centroid M _c when the offset between the centroids is less than about 5 mm. In more stringent applications, the magnetic centroid M _c and the radiographic centroid R _c are considered at least substantially coincident with each other when the offset between the centroids is less than 2 mm or 1 mm. In other applications, the magnetic centroid _Mc is at least approximately coincident with the radiographic centroid when the centroids are separated by a distance less than half the length of the magnetic transponder 120 and / or the marker 100. .

  The imaging element 130 can be made of a material that absorbs a high percentage of incident photons of a radiation beam used to generate a radiographic image and can have a suitable form. For example, when the imaging radiation has a high acceleration voltage in the megavolt range, the imaging element 130 will sufficiently absorb photon fluence incident on the imaging element so that it can be recognized in the resulting radiograph. At least partially, it can be made of a high density material with sufficient thickness and cross-sectional area. Many high energy beams used for therapy have an acceleration voltage of 6MV-25MV, and these beams are often in the range of 5MV-10MV, more specifically in the range of 6MV-8MV, Used to generate radiographic images. Accordingly, the imaging element 130 sufficiently absorbs the incident photon fluence so that it can be recognized in an image generated using a beam having an acceleration voltage of 5 MV-10 MV, and more specifically 6 MV-8 MV. Can be made from the material you want.

Some specific embodiments of the imaging element 130 can be made from gold, tungsten, platinum, and / or other high density metals. In these embodiments, the imaging element 130 may be composed of a material having a density of 19.25 g / cm ³ (tungsten density) and / or a density of about 21.4 g / cm 3 (platinum density). Accordingly, many embodiments of the imaging element 130 have a density of 19 g / cm ³ or greater. However, in other embodiments, the material of the imaging element 130 can have a substantially lower density. For example, imaging elements having low density materials are suitable for applications that use low energy radiation to generate radiographic images. Further, the first and second contrast elements 132 and 134 are different, such that the first contrast element 132 can be made from a first material and the second contrast element 134 can be made from a second material. It can consist of materials.

  Referring to FIG. 8B, the marker 100 can further include a module 140 at the end of the core 128 opposite the capacitor 126. In the embodiment of the marker 100 shown in FIG. 8B, the module 140 is placed symmetrically with respect to the capacitor 126 to increase the symmetry of the radiographic image. As with the first and second contrast elements 132 and 134, the module 140 and capacitor 126 are arranged so that the magnetic centroid of the marker is at least approximately coincident with the radiographic centroid of the marker 100. The Module 140 can be another capacitor identical to capacitor 126, or module 140 can be an electrically inactive element. A suitable electrically inert module includes a ceramic block having the same shape as the capacitor 126 and arranged symmetrically with respect to the coil 122, core 128, and imaging element 130. In still other embodiments, the module 140 can be a different type of electroactive element that is electrically coupled to the magnetic transponder 120.

  One specific process using a marker includes forming an image of the marker using a first modality and then tracking the patient's target and / or marker using a second modality. For example, the position of the marker relative to the target can be determined by forming an image of the marker and target using radiation. The marker and / or target can then be located and tracked using the magnetic field generated by the marker in response to the excitation energy.

The marker 100 shown in FIGS. 8A-8B is expected to produce radiographic images with improved image quality compared to conventional magnetic markers to more accurately determine the relative position between the marker and the patient's target. Is done. For example, FIG. 8C shows a radiographic image 150 of the marker 100 and the target T of the patient. Because the first and second contrast elements 132 and 134 can be constructed from a material that is denser than the components of the magnetic transponder 120, it is expected to be clearer in the radiographic image. The first and second contrast elements 132 and 134 can thus look like dumbbell shaped spherical ends in applications where the components of the magnetic transponder 120 are identifiable in the image. In certain megavolt applications, the components of the magnetic transponder 120 do not appear at all on the radiographic image 150, and the first and second contrast elements 132 and 134 will appear as separate areas that are separate from one another. In either embodiment, the first and second contrast elements 132 and 134 provide a reference coordinate axis that positions the radiographic centroid R _c of the marker 100 within the image 150. Furthermore, the imaging element 130, since the radiographic centroid R _c are arranged to coincide with at least approximately magnetically centroid M _c, relative between the target T and the magnetic centroid M _c The offset or position can be accurately determined using a marker. Thus, the embodiment of the marker 100 shown in FIGS. 8A-8C is expected to reduce errors due to inaccurate estimates of the radiographic image centroid and the magnetic centroid within the radiographic image.

  FIG. 9A is an isometric view of the marker 200 having a cut-out portion to show internal components, and FIG. 9B is a cross-sectional view of the marker 200 taken along line 9B-9B of FIG. 9A. . The marker 200 is similar to the marker 100 shown above in FIG. 8A, and therefore similar reference numbers represent similar components. Marker 200 differs from marker 100 in that it includes an imaging element 230 defined by a single contrast element. The imaging element 230 is generally positioned relative to the magnetic transponder 120 such that the radiographic centroid of the marker 200 is at least approximately coincident with the magnetic centroid of the magnetic transponder 120. More specifically, the imaging element 230 is a ring that extends around the coil 122 in the central region of the magnetic transponder 120. The imaging element 230 can be composed of the same materials described above with respect to the imaging element 130 of FIGS. 8A-8B. The imaging element 230 can have an inner diameter that is approximately equal to the outer diameter of the coil 122 and an outer diameter that enters the casing 110. However, as shown in FIG. 9B, the spacer 231 can be placed between the inner diameter of the imaging element 230 and the outer diameter of the coil 122.

  The marker 200 is expected to function in the same manner as the marker 100 described above. However, the marker 200 does not have two separate contrast elements that provide two separate remote points in the radiographic image. The imaging element 230 nevertheless identifies the radiographic centroid of the marker 200 in the radiographic image and the radiographic centroid of the marker 200 at least approximately matches the magnetic centroid of the magnetic transponder 120. It is much more useful by being able to be arranged.

  FIG. 10A is an isometric view of marker 300 having a cut-out portion, and FIG. 10B is a cross-sectional view of marker 300 taken along line 10B-10B in FIG. 10A. The marker 300 is substantially similar to the marker 200 shown in FIGS. 9A-9B, and therefore similar reference numerals represent similar components in FIGS. 8A-10B. The imaging element 330 can be a high density ring disposed relative to the magnetic transponder 120 such that the radiographic centroid of the marker 300 at least approximately matches the magnetic centroid of the magnetic transponder 120. The marker 300 more specifically includes an imaging element 330 around the casing 110. The marker 300 is expected to function in a manner very similar to the marker 200 shown in FIGS. 9A-9B.

  FIG. 11 is an isometric view with a cut-away portion showing a marker 400 according to another embodiment of the present invention. The marker 400 is similar to the marker 100 shown in FIGS. 8A-8C, and therefore similar reference numbers represent similar components in these figures. The marker 400 has an imaging element 430 that includes a first contrast element 432 at one end of the magnetic transponder 120 and a second contrast element 434 at the other end of the magnetic transponder 120. The first and second contrast elements 432 and 434 are spheres composed of suitable high density materials. Contrast elements 432 and 434 can be composed of, for example, gold, tungsten, platinum, or other high density materials suitable for use in radiographic imaging. The marker 400 is expected to function in a manner similar to the marker 100 described above.

  FIG. 12 is an isometric view with a cut-out portion of the marker 500 according to yet another embodiment of the present invention. The marker 500 is substantially similar to the markers 100 and 400 shown in FIGS. 8A and 11, and thus similar reference numbers represent similar components in these figures. The marker 500 has an imaging element 530 that includes a first contrast element 532 and a second contrast element 534. The first and second contrast elements 532 and 534 can be disposed near the opposing ends of the magnetic transponder 120. The first and second contrast elements 532 and 534 can be discontinuous rings with gaps 535 for reducing eddy currents. Contrast elements 532 and 534 can be composed of the same materials as described above for the contrast elements of other imaging elements according to other embodiments of the present invention.

  Additional embodiments of markers according to the present invention may be incorporated into the casing 110, the core 128 of the magnetic transponder 120 (FIG. 8B), and / or the adhesive 129 in the casing (FIG. 8B), or otherwise with them. An integrated imaging element can be included. For example, particles of high density material can be mixed with ferrite and extruded to form the core 128. In alternative embodiments, particles of high density material can be mixed with glass or other material to form casing 110, or casing 110 can be coated with high density material. In yet another embodiment, the high density material can be mixed with the adhesive 129 and injection molded into the casing 110. In any of these embodiments, the high density material can be incorporated into the combination of casing 110, core 128 and / or adhesive 129. Suitable high density materials can include tungsten, gold and / or platinum as described above.

  The markers described above with reference to FIGS. 8A-12 can be used for the markers 40 in the positioning system 10 (FIGS. 1-7). The positioning system 10 can have several markers with the same type of imaging element, or markers with different imaging elements can be used with the same device. Some additional details of these markers, and other embodiments of markers, are described in US patent application Ser. Nos. 10 / 334,698 and 10 / 746,888, incorporated herein by reference. . For example, the marker may not include any imaging element for low energy radiation applications, or the marker may relate to MRI imaging, as disclosed in US patent application Ser. No. 10 / 334,698. To reduce the problem, it can have a reduced volume of ferrite and metal.

2. Positioning System FIG. 13 is a schematic block diagram of a positioning system 1000 for determining the absolute position of a marker 40 (shown schematically) with respect to a reference coordinate system. Positioning system 1000 includes an excitation source 1010, a sensor assembly 1012, a signal processor 1014 operably coupled to sensor assembly 1012, and a controller 1016 operably coupled to excitation source 1012 and signal processor 1014. Including. The excitation source 1010 is one embodiment of the excitation source 60 described above with reference to FIG. 3, and the sensor assembly 1012 is one embodiment of the sensor assembly 70 described above with reference to FIG. Yes, the controller 1016 is one embodiment of the controller 80 described above with reference to FIG.

  The excitation source 1010 can be tuned to generate a magnetic field having a waveform with energy of a selected frequency that matches the resonant frequency of the marker 40. The magnetic field generated by the excitation source 1010 excites the markers at their respective frequencies. After the marker 40 is excited, the excitation source 1010 is immediately switched to the off position, and the pulsed magnetic field excitation field is terminated while the marker transmits the position signal wirelessly. This allows the sensor assembly 1012 to detect the position signal from the marker 40 without being subject to non-negligible interference from the significantly strong magnetic field from the excitation source 1010. Thus, the excitation source 1010 allows the sensor assembly 1012 to measure the position signal from the marker 40 with a sufficient signal-to-noise ratio so that the signal processor 1014 or controller 1016 can detect the marker 40 relative to the reference coordinate system. The absolute position can be calculated accurately.

a. Excitation Source Still referring to FIG. 13, the excitation source 1010 includes a high voltage power supply 1040, an energy storage device 1042 coupled to the power supply 1040, and a switching network 1044 coupled to the energy storage device 1042. The excitation source 1010 also includes a coil assembly 1046 that couples to the switching network 1044. In one embodiment, power supply 1040 is a 500V power supply, although other power supplies with higher or lower voltages can be used. The energy storage device 1042 in one embodiment is a high voltage capacitor that can be charged by the power source 1040 and maintained in a relatively constant state of charge. The energy storage device 1042 alternately supplies energy to and receives energy from the coils in the coil assembly 1046.

  The energy storage device 1042 can store suitable energy to reduce the voltage drop in the energy storage device while having a low series resistance to reduce power loss. The energy storage device 1042 also has a low series inductance to drive the coil assembly 1046 more effectively. Suitable capacitors for energy storage device 1042 include aluminum electrolytic capacitors used for flash energy applications. Alternative energy storage devices can also include NiCd and lead acid batteries and alternative types of capacitors such as tantalum, thin films, and the like.

  Switching network 1044 includes individual H-bridge switches 1050 (individually identified by reference number 1050a-d), and coil assembly 1046 includes individual source coils 1052 (individually by reference number 1052a-d). Identified). Each H-bridge switch 1050 controls the flow of energy between the energy storage device 1042 and one of the source coils 1052. For example, H-bridge switch # 1 1050a independently controls the flow of energy to / from source coil # 1 1052a, and H-bridge switch # 2 1050b independently controls source coil # 2 1052b. The H-bridge switch # 3 1050c independently controls the energy flow to / from the source coil # 3 1052c, and the H-bridge switch # 4 1050d independently Controls the flow of energy to / from source coil # 4 1052d. Thus, the switching network 1044 independently controls the phase of the magnetic field generated by each of the source coils 1052a-d. The H-bridge 1050 can be configured so that the electrical signals for all source coils 1052 are in phase, or the H-bridge 1050 can be configured so that one or more source coils 1052 are 180 ° out of phase. Can be configured so as to deviate from each other. In addition, the H-bridge switch 1050 is out of phase between 0 ° and 180 ° so that the electrical signals for one or more source coils 1052 simultaneously provide magnetic fields with various phases. It can be constituted as follows.

  The source coils 1052 can be arranged in a coplanar arrangement that is fixed relative to a reference coordinate system. Each source coil 1052 may be a square planar winding arranged to form a flat, substantially straight coil. In different embodiments, the source coil 1052 can take other shapes and arrangements. In one embodiment, the source coil 1052 is an individual conductive wire formed in a layer of a printed circuit board or a wire winding in a foam frame. Alternatively, the source coils 1052 can be formed or placed in different substrates so that two or more source coils are not coplanar with each other. Further, alternative embodiments of the present invention can have fewer or more source coils than shown in FIG.

  The selected magnetic fields from the source coil 1052 combine to form an adjustable excitation field that can have various three-dimensional shapes to excite the marker 40 in any spatial direction within the excitation volume. To do. When the planar arrangement of source coils 1052 is generally horizontal, the excitation volume is located above a range that approximately corresponds to the central region of coil assembly 1046. The excitation volume is adjacent to the coil assembly 1046 and is a three-dimensional space in which the strength of the internal magnetic field is sufficient to properly excite the marker 40.

  FIGS. 14-16 illustrate a source coil 1052 having an AC electrical signal supplied to the source coil in different combinations of phases to generate excitation fields about different axes relative to the XYZ coordinate system shown. 1 is a schematic diagram of a planar arrangement. Each source coil has two outer sides 1112 and two inner sides 1114. Each inner side 1114 of one source coil 1052 is adjacent to the inner side 1114 of another source coil 1052, but the outer side 1112 of all source coils 1052 is connected to any other source coil 1052. Not adjacent.

  In the embodiment of FIG. 14, all source coils 1052a-d receive the same phase alternating electrical signal at the same time. As a result, the current flows in all source coils in the same direction, and the direction of current 1113 flowing along the inner side 1114 of one source coil (eg, source coil 1052a) is two adjacent source coils. The direction of current 1113 flowing along the inner side 1114 of the coil (eg, source coils 1052c and 1052b) is opposite. Thus, the magnetic fields generated along the inner side 1114 cancel each other so that the magnetic field is effectively generated from the current flowing along the outer side 1112 of the source coil. The resulting excitation field formed by the combination of magnetic fields from the source coils 1052a-d shown in FIG. 14 has a magnetic moment 1115 generally in the Z direction within the excitation volume 1109. This excitation field excites a marker parallel to the Z axis or a marker arranged with an angle component in the Z axis direction (that is, not orthogonal to the Z axis).

  FIG. 15 is a schematic diagram of source coils 1052a-d having an alternating electrical signal supplied in a second phase combination to generate a second excitation field having a different spatial orientation. In this embodiment, source coils 1052a and 1052c are in phase with each other, and source coils 1052b and 1052d are in phase with each other. However, source coils 1052a and 1052c are 180 degrees out of phase with source coils 1052b and 1052d. The magnetic fields from the source coils 1052a-d combine to generate an excitation field having a magnetic moment 1217 in the generally Y-axis direction within the excitation volume 1109. Therefore, this excitation field excites a marker parallel to the Y axis or a marker arranged with an angular component in the Y axis direction.

  FIG. 16 is a schematic diagram of source coils 1052a-d having an alternating electrical signal supplied in a third phase combination to generate a third excitation field having a different spatial orientation. In this embodiment, source coils 1052a and 1052b are in phase with each other, and source coils 1052c and 1052d are in phase with each other. However, source coils 1052a and 1052b are 180 degrees out of phase with source coils 1052c and 1052d. The magnetic fields from the source coils 1052a-d combine to produce an excitation field having a magnetic moment 1319 in the general X-axis direction within the excitation volume 1109. Therefore, this excitation field excites a marker parallel to the X axis or a marker arranged with an angular component in the X axis direction.

  FIG. 17 is a schematic diagram of source coils 1052a-d showing the currents that generate the excitation field 1424 for exciting the marker 40 with a vertical axis parallel to the Y axis. The switching network 1044 (FIG. 13) is configured such that the phase of the AC electrical signal supplied to the source coils 1052a-d is similar to the arrangement of FIG. This creates an excitation field 1424 with a magnetic moment in the Y direction to excite the marker 40.

  FIG. 18 further illustrates the ability to spatially adjust the excitation field to excite any marker 40 in various spatial orientations. In this embodiment, the switching network 1044 (FIG. 13) is configured such that the phase of the alternating electrical signal supplied to the source coils 1052a-d is similar to the arrangement shown in FIG. This generates an excitation field with a magnetic moment in the Z direction that excites the marker 40 with a vertical axis parallel to the Z axis.

  The spatial arrangement of the excitation field within the excitation volume 1109 can be quickly adjusted by manipulating the switching network to change phase to the electrical signal supplied to the source coils 1052a-d. As a result, the overall magnetic excitation field can be changed to be oriented in either the X, Y or Z direction within the excitation volume 1109. This adjustment of the spatial orientation of the excitation field reduces or eliminates blind spots in the excitation volume 1109. Thus, the marker 40 in the excitation volume 1109 can be excited by the source coils 1052a-d regardless of the spatial orientation of the lead-free marker.

  In one embodiment, the excitation source 1010 couples to the sensor assembly 1012 so that the switching network 1044 (FIG. 13) can be configured with X, Y, and Z depending on the strength of the signal received by the sensor assembly. Adjust the pulse generation orientation of the excitation field along the axis. If the position signal from marker 40 is inadequate, switching network 1044 causes subsequent excitation to source coils 1052a-d to generate excitation fields with moments in different axes or directions between axes. During the pulse delivery, the spatial orientation of the excitation field can be changed automatically. The switching network 1044 can be operated until the sensor assembly 1012 receives a sufficient position signal from the marker.

  The excitation source 1010 shown in FIG. 13 excites the source coils 1052a-d to energize the marker 40 during the excitation phase, and then the attenuation position where the sensor assembly 1012 is transmitted wirelessly by the marker 40. During the detection phase of detecting the signal, the source coils 1052a-d are actively de-excited alternately. In order to actively excite and de-energize source coils 1052a-d, switching network 1044 transmits stored energy from energy storage device 1042 to source coils 1052a-d, and then source coil 1052a. Re-transferring energy from -d to the energy storage device 1042 is configured to alternate. Switching network 1044 alternates between first and second “on” positions such that the voltage across source coil 1052 alternates between positive and negative polarities. For example, when the switching network 1044 is switched to a first “on” position, energy in the energy storage device 1042 flows toward the source coils 1052a-d. When the switching network 1044 is switched to the second “on” position, energy in the source coils 1052a-d is actively extracted from the source coils 1052a-d and returned back to the energy storage device 1042. The polarity is reversed. As a result, the energy in the source coils 1052a-d is immediately returned to the energy storage device 1042, suddenly terminating the excitation field transmitted from the source coils 1052a-d, and conserving power consumption in the energy storage device 1042. . This removes the excitation energy from the environment so that the sensor assembly 1012 can detect the position signal from the marker 40 without interference from the very large excitation energy from the excitation source 1010. Some additional details and alternative embodiments of the excitation source 1010 are US patent application Ser. No. 10 / 213,980 filed Aug. 7, 2002, which is hereby incorporated by reference in its entirety. , Currently disclosed in U.S. Pat. No. 6,822,570.

b. Sensor Assembly FIG. 19A is an exploded isometric view showing some components of the sensor assembly 1012 used in the positioning system (FIG. 13). Sensor assembly 1012 includes a detection unit 1601 having a plurality of coils 1602 formed on or supported by panel 1604. Coil 1602 may be a field sensor or a magnetic flux sensor arranged in sensor array 1605.

  Panel 1604 can be a substantially non-conductive material, such as a sheet of KAPTON® from DuPont. KAPTON® is particularly useful when very stable, tough, and thin films are needed (such as to prevent radiation beam contamination), but the panel 1604 is made from other materials and other It can be a shape. For example, FR4 (epoxy glass substrate), GETEK or other Teflon-based substrate, and other commercially available materials can be used for the panel 1604. Further, the panel 1604 can be a flat and highly planar structure, but in other embodiments the panel may be curved along at least one axis. In either embodiment, the field sensors (eg, coils) are arranged in a local planar array in which the plane of one field sensor is at least substantially coplanar with the plane of an adjacent field sensor. . For example, the angle between the plane defined by one coil and the plane defined by adjacent coils can be approximately 0 ° to 10 °, more typically less than 5 °. It is. However, in some situations, one or more coils can be at an angle greater than 10 ° relative to other coils in the array.

  The sensor assembly 1012 shown in FIG. 19A can optionally include a core 1620 that is bonded to the panel 1604. The core 1620 can be a support component made from a rigid material, or the core 1620 can be a low density foam, such as a closed cell Lohacell foam. The core 1620 is preferably a stable layer having a low coefficient of thermal expansion so that the shape of the sensor assembly 1012 and the relative orientation between the coils 1602 remain within a predetermined range over the entire operating temperature range.

  The sensor assembly 1012 can further include a first outer cover 1630a on one side of the detection subsystem and a second outer cover 1630b on the opposite side. The first and second outer covers 1630a-b can be thin thermally stable layers, such as Kevlar or surmount films. Each of the first and second outer covers 1630 a-b can include an electrical shield 1632 that blocks unwanted external electric fields from reaching the coil 1602. The electrical shield 1632 may be a plurality of parallel legs of a gold-plated copper strip that outlines a comb shield in an arrangement commonly referred to as a Faraday shield. It will be appreciated that the shield can be formed from other materials suitable for the shield. The electrical shield can be formed on the first and second outer covers using printed circuit board manufacturing techniques or other techniques.

  Panel 1604 with coil 1602 can be bonded to core 1620 using an adhesive or other type of adhesive. Similarly, the first and second outer covers 1630a-b can be bonded to the assembly of the panel 1604 and the core 1620. The laminated assembly forms a rigid structure that secures the array of coils 1602 in a defined arrangement over a wide operating temperature range. Accordingly, the sensor assembly 1012 does not substantially distort across its surface during operation. For example, the sensor assembly 1012 can hold the array of coils 1602 in a fixed position with a strain of ± 0.5 mm or less, and in some cases ± 0.3 mm or less. The rigidity of the detection subsystem provides highly accurate and repeatable real-time monitoring of the exact location of the lead-free marker.

  In yet another embodiment, sensor assembly 1012 can further include a plurality of source coils that are components of excitation source 1010. One suitable arrangement for coupling the sensor assembly 1012 with the source coil is a US patent application summary entitled “Panel Sensor / Source Array Assembly” filed 30 December 2002, incorporated herein by reference. No. 10 / 334,700.

  FIG. 19B further illustrates an embodiment of the detection unit 1601. In this embodiment, the detection unit 1601 includes 32 sensor coils 1602, each coil 1602 being associated with a separate channel 1606 (indicated individually as channels from “Ch 0” to “Ch 31”). . The overall dimensions of panel 1604 are approximately 40 cm x 54 cm, while array 1605 has a first dimension D1 of approximately 40 cm and a second dimension D2 of approximately 40 cm. In alternative embodiments, the array 1605 can have other dimensions or other arrangements (eg, circular). In addition, the array 1605 can have more or fewer coils, such as 8-64 coils, and the number of coils can be a power of two.

  Coil 1602 can be a conductive trace or deposit of copper or another suitable conductive metal formed on panel 1604. Each coil 1602 has a trace having a width of about 0.15 mm and a spacing between adjacent turns in each coil of about 0.13 mm. The coils 1602 have about 15 to 90 turns, and in certain applications, each coil has about 40 turns. A coil with less than 15 turns may not be sensitive enough for some applications, and a coil with more than 90 turns will cause an excess voltage from the source signal during excitation and It can lead to excessive settling time due to the low self-resonant frequency. However, in other applications, the coil 1602 can have less than 15 turns or more than 90 turns.

  As shown in FIG. 19B, the coils 1602 are arranged in a square spiral, but other arrangements such as circular, combined hexagonal, triangular, etc. arrangements can also be used. Such square spirals use a large percentage of surface area to improve the signal to noise ratio. Square coils also simplify design layout and array modeling compared to circular coils. For example, a circular coil can waste surface area to couple the magnetic flux from the marker 40. The coil 1602 has an inner dimension of about 40 mm and an outer dimension of about 62 mm, although other dimensions are possible depending on the application. Sensitivity can be improved by using an inner dimension that is as close to the outer dimension as possible within manufacturing tolerances. In some embodiments, the coils 1602 are configured to be the same or substantially similar to each other.

  The pitch of the coils 1602 in the array 1605 is at least partially a function of the shortest distance between the marker and the coil array. In one embodiment, the coils are arranged at a pitch of about 67 mm. This particular arrangement is particularly suitable when the wireless marker 40 is positioned approximately 7-27 cm from the sensor assembly 1012. If the wireless marker is closer than 7 cm, the detection subsystem can include sensor coils arranged at a smaller pitch. In general, smaller pitches are desirable when wireless markers are detected at relatively short distances from the array of coils. For example, the pitch of the coils 1602 is about 50% to 200% of the shortest distance between the marker and the array.

  In general, the dimensions and placement of the array 1605 and the coils 1602 within the array depend on their operating frequency range, the distance from the marker 40 to the array, the signal strength of the marker, and several other factors. One skilled in the art will readily recognize that other dimensions and arrangements can be used, at least in part, depending on the desired frequency region and marker-to-coil distance.

  The array 1605 is dimensioned to provide a large aperture for measuring the magnetic field emitted by the marker. Because the marker signal is much smaller than the source signal and other magnetic fields in the room, the signal emitted by the implantable marker that transmits the marker signal wirelessly in response to the wirelessly transmitted energy source is accurate. Measuring can be a particularly challenging problem. The dimensions of the array 1605 can be selected to preferentially measure the near field of the marker while reducing interference from non-near field sources. In one embodiment, the array 1605 is dimensioned with a maximum dimension D1 or D2 across the coil occupying surface area that is about 100% to 300% of a predetermined maximum detection distance at which the marker is separated from the coil plane. . Thus, the dimensions of the array 1605 are determined by identifying the distance that the marker should be separated from the array in order to accurately measure the marker signal, and then the coil has a maximum dimension of the array from about 100% of that distance. It arrange | positions so that it may become 300%. The maximum dimension of the array 1605 can be, for example, about 200% of the detection distance at which the marker is separated from the array. In one particular embodiment, the marker 40 has a detection distance of 20 cm, and the maximum dimension of the array of coils 1602 is between 20 cm and 60 cm, and more specifically 40 cm.

  A coil array having the maximum dimensions described above is particularly useful because it inherently provides a filter that reduces interference from non-near field sources. Thus, one aspect of some embodiments of the present invention is that the array preferentially measures near-field sources (ie, fields generated by markers) and removes disturbances from non-near-field sources. The size of the array is determined based on the signal from the marker.

  The coils 1602 are electromagnetic field sensors that receive the magnetic flux generated by the wireless marker 40 through the inner portion or area of each coil and then generate a current signal that represents or is proportional to the amount or magnitude of the magnetic field component. The magnetic field component is also perpendicular to the plane of each coil 1602. Each coil represents a separate channel, so each coil outputs a signal to one of 32 output ports 1606. The following preamplifier can be provided in each output port 1606. Placing the preamplifier (or impedance buffer) in the vicinity of the coil minimizes capacitive loading on the coil, as described herein. Although not shown, detection unit 1601 also includes conductive traces or conductive paths that transmit signals from each coil 1602 to a corresponding output port 1606 to define separate channels. The port is then coupled to a connector 1608 formed on a panel 1604 to which a suitable form of plug and connecting cable can be attached.

  The detection unit 1601 may also include other circuitry such as on-board memory or electrically erasable programmable read only memory (EEPROM) 1610. The EEPROM 1610 can store manufacturing information such as a serial number, a revision number, and a manufacturing date. The EEPROM 1610 can also store calibration data for each channel and run time records. The run time gives an indication of the total radiation dose that the array has been exposed to, and that indicator can alert the system when the detection subsystem needs to be replaced.

  Although only one plane is shown, additional coils or electromagnetic field sensors can be placed perpendicular to the panel 1604 to assist in determining the three-dimensional position of the wireless marker 40. Adding other size coils or sensors can increase the total energy received from the wireless marker 40, but will increase the complexity of the array excessively. The present inventor has found that the three-dimensional coordinates of the wireless marker 40 can be detected using the planar array shown in FIGS. 19A-B.

  Implementing sensor assembly 1012 includes several considerations. First, the coil 1062 may not be given an ideal open circuit. Instead, the coils are mostly parasitic capacitance due to traces or conductive paths connecting the coil 1602 to the preamplifier, and the attenuation network (described below) and the preamplifier input impedance (although a low input impedance is preferred). ) Is likely to be loaded. These combined loads produce a current flow when the coil 1602 couples with the changing magnetic flux. Thus, any one coil 1602 couples not only to the magnetic flux from the wireless marker 40, but to the magnetic flux from all other coils as well. These current flows must be considered in downstream signal processing.

  A second consideration is the capacitive load on the coil 1602. In general, it is desirable to minimize the capacitive load on the coil 1602. The capacitive load forms a resonant circuit for the coil itself, which results in excessive voltage overshoot when the excitation source 1010 is powered. Such voltage overshoot should be limited or attenuated by an attenuation or “snubbing” network throughout the coil 1602. Larger capacitive loads require a lower impedance attenuation network, which can result in substantial power consumption and heating in the attenuation network.

  Another consideration is to use a low noise preamplifier. The preamplifier can also be radiation tolerant because one application of the sensor assembly 1012 is a radiation therapy system using a linear accelerator (LINAC). As a result, PNP bipolar transistors and isolated devices are preferred. In addition, a DC coupling circuit may be preferred when good settling time cannot be achieved with an AC circuit or output, especially when the analog-to-digital converter cannot handle wide oscillations in the AC output signal.

  FIG. 20 illustrates one embodiment of a snubbing network 1702 with a differential amplifier 1704, for example. Snubbing network 1702 includes two sets of series coupled resistors and a capacitor that bridges between them. The bias circuit 1706 allows adjustment of the differential amplifier, while the calibration input 1708 allows both input legs of the differential amplifier to be balanced. Coil 1602 is coupled to the input of differential amplifier 1704 with a pair of high voltage protection diodes 1710. The DC offset can be adjusted by a pair of resistors (shown as having a zero value) coupled to the base of the input transistor of differential amplifier 1704. Additional protection circuitry is provided such as an ESD protection diode 1712 at the output, and a filter capacitor (shown as having a 10 nF value).

c. Signal Processor and Controller The signal processor 1014 and controller 1016 shown in FIG. 13 receives the signal from the sensor assembly 1012 and calculates the absolute position of the marker 40 in the reference coordinate system. Suitable signal processing systems and algorithms are described in U.S. Patent Application Serial Nos. 10 / 679,801, 10 / 749,478, 10 / 750,456, 10 / 750,164, 10/750. 165, 10 / 749,860, and 10 / 750,453, all of which are incorporated herein by reference.

A study based on an experimental phantom was conducted to determine the effectiveness of this system for real-time tracking. In this experiment, a specially manufactured 4D stage was constructed that allowed any motion in three axes to be accelerated to 10 cm / sec in each dimension with an accuracy of 0.3 mm. Position accuracy was measured by a 3D digitizing arm attached to the stage system. As shown in FIG. 21, two ellipses were created by peak-to-peak motion of 2 cm, 4 cm and 2 cm, and 1 cm, 2 cm and 1 cm in the x, y and z directions, respectively. Three cycles corresponding to 15, 17 and 20 breaths per minute were used. A single transponder was used at integration times of 33 ms, 67 ms and 100 ms, and two transponders were used at integration times of 67 ms and 100 ms. The transponder was placed inside a specially made phantom mounted on a 4D stage. Experiments were performed using an isocenter 14 cm away from the AC magnetic array to mimic the location of an average lung cancer patient. The 4D stage scanned each trajectory as the real-time tracking system measured the position of the transponder. The measured position was compared with the position of the phantom. The characteristics of the effect of ellipse size, speed, number of transponders and integration time were investigated.

Experimental Summary As shown in FIG. 22, the root mean square (RMS) error was less than 1 mm for each ellipse, period, and transponder integration time. The system was able to track the target point over the entire elliptical path, for example, within a large elliptical trajectory at 17 breaths per minute. FIG. 23 is a histogram of positioning errors, showing that the error range is small for each measurement point. As shown in FIG. 24, the RMS error was high in the region where the speed increased in most of the trajectories. For this experiment, the single transponder system performed slightly better than the dual transponder system and the best system was a single transponder with an integration time of 67 ms.

The foregoing description of the conclusions illustrated embodiment, including what is described in the abstract, it, or be limited to the precise form disclosed the present invention and are not intended to be exhaustive . While specific embodiments and examples have been described herein for purposes of illustration, various equivalent modifications may be made without departing from the spirit and scope of the invention, as those skilled in the art will recognize. Can be applied. The teachings of the invention provided herein can be applied to target positioning and tracking systems, although exemplary systems are not necessarily generally described above.

  The various embodiments described above can be combined to provide further embodiments. All U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications cited in this specification and / or listed in application data sheets are: The entirety of which is incorporated herein by reference. Aspects of the invention can be modified to use various patent, application and publication systems, devices and concepts, if necessary, to provide further embodiments of the invention.

  These and other changes can be made in light of the above detailed description. In general, the terms used in the appended claims should not be construed to limit the invention to the specific embodiments disclosed in the specification and the claims, but are selected targets within the body. It should be construed to include all systems for locating and monitoring a target operating in accordance with the claims to provide an apparatus and method for determining, monitoring and / or tracking the position of the target. Accordingly, the invention is not limited except as by the appended claims.

1 is a side view of a tracking system used for target positioning and monitoring, according to one embodiment of the invention. FIG. The excitable marker is shown to be implanted within or adjacent to the target within the patient. FIG. 6 is a schematic elevational view of a patient on a movable support and a marker implanted in the patient's body. 1 is a side view schematically illustrating a positioning system and a plurality of markers implanted in a patient according to an embodiment of the present invention. FIG. 4 is a flowchart of an integrated radiotherapy process using real-time target tracking for radiotherapy according to an embodiment of the present invention. 2 is a CT image display illustrating one aspect of a system and method for real-time tracking of a target in radiation therapy and other medical applications. It is a figure which shows schematically the reference coordinate system of CT scanner. 4 is a screen shot of a user interface for displaying objective output according to one embodiment of the invention. 2 is an isometric view of a radiation exposure period according to one embodiment of the present invention. FIG. 2 is an isometric view of a marker for use with a positioning system according to one embodiment of the present invention. FIG. FIG. 8B is a cross-sectional view taken along line 8B-8B of the marker of FIG. 8A. 9 is an example of a radiographic image of the marker of FIGS. 8A-8B. 6 is an isometric view of a marker for use with a positioning system according to another embodiment of the present invention. FIG. FIG. 9B is a cross-sectional view taken along line 9B-9B of the marker of FIG. 9A. 6 is an isometric view of a marker for use with a positioning system according to another embodiment of the present invention. FIG. FIG. 10B is a cross-sectional view taken along line 10B-10B of the marker of FIG. 10A. 6 is an isometric view of a marker for use with a positioning system according to another embodiment of the present invention. FIG. FIG. 6 is an isometric view of a marker for use with a positioning system according to yet another embodiment of the present invention. 1 is a schematic block diagram of a positioning system for use in target tracking according to one embodiment of the invention. FIG. FIG. 6 is a schematic diagram of an arrangement of coplanar power supply coils that carry electrical signals of a first phase combination for generating a first excitation field. FIG. FIG. 6 is a schematic diagram of an arrangement of coplanar power supply coils that carry electrical signals of a second phase combination for generating a second excitation field. FIG. FIG. 6 is a schematic diagram of an arrangement of coplanar power supply coils that carry electrical signals of a third phase combination for generating a third excitation field. Fig. 6 is a schematic diagram of an arrangement of coplanar power coils showing a magnetic excitation field for activating markers in a first spatial direction. 4 is a schematic diagram of a coplanar power coil arrangement showing a magnetic excitation field for activating a marker in a second spatial direction. FIG. 3 is an exploded isometric view showing individual components of a sensor assembly for use with a positioning system according to one embodiment of the present invention. FIG. 19B is a plan view of a detection unit used in the sensor assembly of FIG. 19A. 19B is a schematic diagram of a preamplifier for use with the sensor assembly of FIG. 19A. 3 is an exemplary tumor motion ellipse graph from an experimental phantom-based study of the system. Figure 3 is a graph of root mean square (RMS) error from a study based on an experimental phantom of the system. FIG. 6 is an exemplary histogram of positioning errors from a study based on an experimental phantom of the system. FIG. Figure 6 is a graph of position error as a function of speed from an experimental phantom-based study of the system.

Claims (78)

A method for tracking a target in a human patient in a medical application using a marker fixed in the patient so as to be substantially fixed to the target,
Collecting position data of the marker;
Determining the position of the marker in an external reference coordinate system based on the position data;
(A) generating an objective output in the external reference coordinate system, corresponding to the position of the marker, and (b) given at a frequency where the tracking error is less than 5 mm;
Including methods.   The marker comprises a small transponder that wirelessly transmits a position signal in response to non-ionized excitation energy transmitted wirelessly, and collecting the position data includes detecting the position signal. The method according to claim 1.   The marker is configured to be implanted within the patient, and the method further includes implanting the marker at a location at least proximate to the target such that the marker moves in direct correlation with movement of the target. The method according to claim 2, wherein:   The marker is configured to be implanted within the patient and includes a small lead-free marker having a transponder that wirelessly transmits a position signal in response to non-ionized excitation energy transmitted wirelessly, and the method implants the marker The method of claim 1 including the step of: collecting the position data comprises detecting the position signal.   The marker includes a small AC magnetic transponder that wirelessly transmits an AC magnetic position signal in response to a wirelessly transmitted AC magnetic field, and the step of collecting the position data includes detecting an AC magnetic position signal. The method of claim 1, comprising:   The method of claim 1, wherein the objective output is generated without artificial interpretation of at least one of the position data and the determined position of the marker.   The method of claim 1, wherein the objective output includes three-dimensional coordinates in the external reference coordinate system.   The method of claim 1, wherein the objective output comprises an offset value between the target position and a desired target position determined in a computer system. The position data is collected at time t _n , and providing the objective output corresponding to the position of the target includes providing the objective output for about 15 seconds with a waiting time within about 5 seconds from time t _n. The method of claim 1, comprising providing to at least one of a user interface, a memory device, a computer, and a medical device with a period of less than a second. The waiting time is characterized in that from time t _n in the period of more than about 2 seconds within about 2 seconds, The method of claim 9. The method of claim 9, wherein the waiting time is within about 1 second from time t _n in a period of about 1 second or less. The method of claim 9, wherein the waiting time is within about 100 milliseconds from time t _n in a period of about 200 milliseconds or less. The method of claim 9, wherein the waiting time is within about 50 milliseconds from time t _n in a period of about 50 milliseconds or less.   The method of claim 9, wherein the period is about 12.5 milliseconds.   The method of claim 9, wherein the period is about 16.67 milliseconds.   The method of claim 9, wherein the period is about 20 milliseconds.   2. The method of claim 1, further comprising positioning the patient to position the target at a desired location relative to an isocenter of a radiation delivery device while performing the collection, determination, and delivery procedures. The method described in 1.   The method of claim 1, further comprising irradiating the patient with a high intensity ionization beam directed to an isocenter of a radiation irradiator while performing the collection, determination, and delivery procedures.   The method of claim 18, further comprising controlling at least one of a patient position and a parameter of the high intensity ionization beam while performing the acquisition, determination and delivery procedures.   Controlling the on / off state of the non-ionized beam such that the non-ionized beam is turned on when the target is shown to be in a desired position relative to the machine isocenter. 20. A method according to claim 19, characterized.   20. The method of claim 19, further comprising moving the patient to place the target at a desired location relative to the machine center.   The method of claim 19, further comprising changing the non-ionized beam shape.   Providing the objective output in the external reference coordinate system includes providing the objective output at least substantially simultaneously with collecting position data used to determine the position of the marker. The method of claim 1, wherein:   The method of claim 1, wherein the frequency includes providing a plurality of objective outputs during beam on. A method of tracking a target in real time using a marker embedded in the patient in a position associated with the target in radiation therapy for treating a target in the patient,
Collecting the marker position data at time t _n ;
Determining the position of the marker in an external reference coordinate system based on the position data;
Providing an objective output corresponding to the position of the target to a user interface, a memory device and / or a radiation irradiator within a waiting time within 2 seconds from time t _n ;
Repeating the supply procedure at least every 2 seconds;
Including methods.   The marker comprises a small transponder that wirelessly transmits a position signal in response to non-ionized excitation energy transmitted wirelessly, and the step of collecting the position data includes the position signal transmitted wirelessly by the marker. The method of claim 25, comprising the step of detecting.   The marker includes a small AC magnetic transponder that wirelessly transmits an AC magnetic position signal in response to an AC magnetic field transmitted wirelessly, and the step of collecting the position data is an alternating current transmitted wirelessly by the marker. 26. A method according to claim 25, comprising detecting a magnetic position signal.   26. The method of claim 25, wherein the objective output includes an offset coordinate between the position of the target and an isocenter of the radiation irradiator. Providing the objective output comprises: providing the offset coordinates at a period of about 1 millisecond to about 1 second within a waiting time of about 1 millisecond to about 1 second from time t _n ; 29. The method of claim 28, comprising sending to the memory device and / or the radiation irradiator. The step of providing the objective output comprises the step of supplying the offset coordinates with a period of about 1 millisecond to about 200 milliseconds within a waiting time of about 1 millisecond to about 100 milliseconds from time t _n. 29. A method according to claim 28, comprising sending to an interface, the memory device and / or the radiation delivery device. The step of providing the objective output comprises the step of supplying the offset coordinates with a period of about 20 milliseconds to about 50 milliseconds within a waiting time of about 10 milliseconds to about 50 milliseconds from time t _n. 29. A method according to claim 28, comprising sending to an interface, the memory device and / or the radiation delivery device. The objective output includes coordinates in an external reference coordinate system with respect to the position of the target, and providing the objective output is within a waiting time of about 10 milliseconds to about 100 milliseconds from time t _n . 26. The method of claim 25, comprising sending the coordinates to the user interface with a period of about 10 milliseconds to about 50 milliseconds.   The method of claim 32, wherein the period is about 12.5 milliseconds.   The method of claim 32, wherein the period is approximately 16.67 milliseconds.   The method of claim 32, wherein the period is about 20 milliseconds.   The method of claim 1, further comprising positioning the patient to position the target at a desired location relative to the isocenter of the radiation delivery device while performing the collection, determination, and delivery procedures. 26. The method according to 25. The objective output includes an offset coordinate between the position of the target and a desired position of the target relative to the isocenter of the radiation irradiator, and providing the objective output is about 1 from time t _n. Sending the offset coordinates to the user interface, the memory device and / or the radiation irradiator with a period of about 1 millisecond to about 200 milliseconds within a waiting time of milliseconds to about 100 milliseconds; 37. The method of claim 36, comprising: The step of supplying the objective output comprises the step of supplying the offset coordinates with a period of about 10 milliseconds to about 50 milliseconds within a waiting time of about 10 milliseconds to about 100 milliseconds from time t _n. 38. The method of claim 37, comprising the step of: Supplying step the objective output within the time t _n of about 1 millisecond to about 100 milliseconds waiting time, with a period of about 1 millisecond to about 50 milliseconds, the offset coordinates, the radiation irradiation device 38. The method of claim 37, wherein the radiation irradiator automatically moves a patient support table according to the offset coordinates.   26. The method of claim 25, further comprising irradiating the target with a radiation beam from the radiation irradiator while performing the collection, determination and delivery procedures. The objective output includes offset coordinates between the position of the target and a desired position of the target relative to the isocenter of the radiation irradiator, and the step of providing the objective output is approximately 1 mm from time t _n. 41. The method of claim 40, comprising sending the offset coordinates to the radiation irradiator with a period of about 1 millisecond to about 200 milliseconds within a waiting time of seconds to about 100 milliseconds. Method.   42. The method of claim 41, further comprising controlling a parameter of the radiation irradiator according to the offset coordinates.   Controlling the parameters of the radiation irradiator includes terminating the radiation beam when the offset coordinates exceed a predetermined value indicating that the target is outside the isocenter tolerance. 43. The method of claim 42, wherein:   43. The method of claim 42, wherein controlling the parameters of the radiation irradiator includes automatically moving a patient support table according to the offset coordinates. A method of tracking a target in radiation therapy for treating a target in a patient, comprising:
Obtaining position data of a marker disposed at a position related to the target in the patient body;
Determining the position of the marker in an external reference coordinate system based on the position data;
An objective output to the user interface indicating the position of the target based on the determined position of the marker; (a) a pause in displaying the target position on the user interface is immediately Providing at a sufficiently high frequency so as to be unrecognizable, and (b) at a substantially short latency so as to be at least substantially simultaneous with acquisition of the position data of the marker;
Including methods.   The marker includes a small transponder that wirelessly transmits a position signal in response to non-ionized excitation energy transmitted wirelessly, and the step of obtaining the position data includes the position signal transmitted wirelessly from the marker. 46. The method of claim 45, comprising the step of detecting.   The marker comprises a small AC magnetic transponder that wirelessly transmits an AC magnetic position signal in response to an AC magnetic field transmitted wirelessly, and obtaining the position data is wirelessly transmitted by the marker 46. A method according to claim 45, comprising detecting an alternating magnetic position signal. The position data is acquired at time t _n , and the objective output includes an offset coordinate between the position of the target and a desired position of the target with respect to the isocenter of the radiation irradiation apparatus. 46. The method of claim 45. The step of providing the objective output comprises the step of supplying the offset coordinates with a period of about 1 millisecond to about 1 second within a waiting time of about 1 millisecond to about 1 second from time t _n , and the user interface and 49. The method according to claim 48, comprising the step of sending to the radiation application device. The step of providing the objective output comprises the step of supplying the offset coordinates with a period of about 1 millisecond to about 200 milliseconds within a waiting time of about 1 millisecond to about 100 milliseconds from time t _n. 49. The method according to claim 48, comprising the step of sending to an interface and / or said radiation delivery device. The step of providing the objective output comprises the step of supplying the offset coordinates with a period of about 20 milliseconds to about 50 milliseconds within a waiting time of about 10 milliseconds to about 50 milliseconds from time t _n. 49. The method according to claim 48, comprising the step of sending to an interface and / or said radiation delivery device. The position data is acquired at time t _n , the objective output includes coordinates associated with the position of the target in the external coordinate system, and the step of providing the objective output is about 10 mm from time t _n. 46. The method of claim 45, comprising sending the coordinates to the user interface with a period of about 10 milliseconds to about 50 milliseconds within a waiting time of seconds to about 100 milliseconds. Method.   46. The method of claim 45, further comprising positioning the patient to position the target at a desired location relative to an isocenter of a radiation delivery device while performing the collection, determination, and delivery procedures. The method described in 1. The position data is acquired at time t _n , and the objective output includes an offset coordinate between the position of the target and a desired position of the target with respect to the isocenter of the radiation irradiator, and the objective data Providing a dynamic output includes, during a waiting time of about 1 millisecond to about 100 milliseconds from time t _n , the offset coordinates in the user interface and / or with a period of about 1 millisecond to about 200 milliseconds. 46. A method according to claim 45, further comprising the step of sending to the radiation irradiator. Providing the objective output includes providing the offset coordinates to the user interface in a period of about 10 milliseconds to about 50 milliseconds within a waiting time of about 10 milliseconds to about 100 milliseconds from time t _n; 55. The method of claim 54, comprising the step of: The step of supplying the objective output includes the step of supplying the offset coordinates to the radiation irradiating apparatus at a period of about 1 millisecond to about 50 milliseconds within a waiting time of about 1 millisecond to about 100 milliseconds from time t _n. 55. The method of claim 54, wherein the radiation delivery device moves a patient support by the offset coordinates.   46. The method of claim 45, further comprising irradiating the target with a radiation beam from a radiation irradiator while performing the acquisition, determination and delivery procedures. The position data is acquired at time t _n , and the objective output includes an offset coordinate between the position of the target and a desired position of the target with respect to the isocenter of the radiation irradiator, the objective data The step of supplying an output includes the step of sending the offset coordinates to the radiation irradiating apparatus with a period of about 1 millisecond to about 200 milliseconds within a waiting time of about 1 millisecond to about 100 milliseconds from time t _n. 58. The method of claim 57, comprising:   59. The method of claim 58, further comprising controlling a parameter of the radiation irradiator according to the offset coordinates.   Controlling the parameters of the radiation irradiator includes terminating the radiation beam when the offset coordinates exceed a predetermined value indicating that the target is outside the tolerance range of the isocenter. 60. The method of claim 59.   60. The method according to claim 59, wherein the step of controlling the parameters of the radiation irradiator comprises automatically moving a patient support according to the offset coordinates. A radiation therapy system for treating a patient target with a marker embedded in the patient at a location associated with the target,
A radiation irradiator comprising a beam generator for generating an ionizing radiation beam, an isocenter, and an sighting device for directing the beam toward the isocenter
A detector for obtaining position data of the marker at time t _n ;
A computer operatively coupled to the detector to receive the position data, wherein the position of the marker is determined based on the position data, and an objective output indicative of the position of the target is obtained at time t a computer having a computer operable medium for supplying to a user interface, a memory device and / or a radiation irradiator with a period of 2 seconds or less within a waiting time of 2 seconds or less from _n
A system comprising:   An excitation source configured to wirelessly transmit non-ionized excitation energy and a marker having a small transponder configured to wirelessly transmit a position signal in response to the wirelessly transmitted non-ionized excitation energy; 63. The radiation therapy system of claim 62, further comprising: the detector configured to detect the position signal transmitted wirelessly by the marker.   The detection comprising: an excitation source configured to wirelessly transmit an alternating magnetic field; and a marker having a small alternating magnetic transponder that wirelessly transmits an alternating magnetic position signal in response to the wirelessly transmitted alternating magnetic field 63. A radiation therapy system according to claim 62, wherein the instrument comprises a coil configured to detect the alternating magnetic position signal transmitted wirelessly by the marker.   64. The radiation therapy system of claim 62, wherein the objective output includes offset coordinates between the position of the target and a desired position of the target with respect to an isocenter of the radiation irradiator. . The computer operable medium is configured to transfer the offset coordinates to the user interface, the memory device at a period of about 1 millisecond to about 1 second within a waiting time of about 1 millisecond to about 1 second from time t _n. 66. The radiation treatment system according to claim 65, wherein the radiation treatment system is sent to the radiation irradiation apparatus. The computer-readable medium stores the offset coordinates in the user interface, the memory in a period of about 1 millisecond to about 200 milliseconds within a waiting time of about 1 millisecond to about 100 milliseconds from time t _n. 66. Radiation therapy system according to claim 65, characterized in that it is sent to a device and / or said radiation irradiator. The computer-readable medium stores the offset coordinates in the user interface, the memory in a period of about 20 milliseconds to about 50 milliseconds within a waiting time of about 10 milliseconds to about 50 milliseconds from time t _n. 66. Radiation therapy system according to claim 65, characterized in that it is sent to a device and / or said radiation irradiator. The objective output includes coordinates in the external reference coordinate system with respect to the position of the target, and the computer-operable medium is about 10 to about 10 milliseconds to about 100 milliseconds from time t _n. 66. The radiation therapy system of claim 65, wherein the coordinates are sent to the user interface with a period of milliseconds to about 50 milliseconds.   63. Radiation according to claim 62, wherein the computer operable medium sends a signal to position the patient to position the target at a desired location relative to the isocenter of the radiation delivery device. Treatment system. The objective output includes offset coordinates between the isocenter and the position of the target the radiation irradiating device, wherein the computer operable medium, from the time t _n of about 1 millisecond to about 100 milliseconds waiting 71. The offset coordinates are sent to the user interface, the memory device, and / or the radiation irradiator in a period of about 1 millisecond to about 200 milliseconds in time. Radiation therapy system. The computer operable medium sends the offset coordinates to the user interface with a period of about 10 milliseconds to about 50 milliseconds within a waiting time of about 10 milliseconds to about 100 milliseconds from time t _n. 72. The radiation therapy system according to claim 71, wherein: The computer operable medium sends the offset coordinates to the radiation irradiator with a period of about 1 millisecond to about 50 milliseconds within a waiting time of about 1 millisecond to about 100 milliseconds from time t _n , 72. The radiation therapy system according to claim 71, wherein the radiation irradiating apparatus is configured to automatically move a patient support base according to the offset coordinates. The objective output includes offset coordinates between the isocenter and the position of the target the radiation irradiating device, wherein the computer operable medium, from the time t _n of about 1 millisecond to about 100 milliseconds waiting 64. The radiation therapy system of claim 62, wherein the coordinates are sent to the radiation delivery device in a period of about 1 millisecond to about 200 milliseconds in time. A tracking system for treating a patient's target with a marker embedded in the patient at a location associated with the target,
A detector for obtaining position data of the marker at time t _n ;
A computer operatively coupled to the detector for receiving the position data, wherein the position of the marker is determined based on the position data and within a waiting time of 10-200 milliseconds from time t _n A computer having a computer operable medium that provides an objective output indicative of the position of the target at a period of 10-100 milliseconds;
A system comprising: A method of treating a patient target using ionizing radiation comprising:
Generating a beam of ionizing radiation and directing the beam to the target;
Collecting position information of markers implanted at a position associated with the target within a patient while directing the beam to the beam isocenter;
Providing an objective output indicative of the position of the target relative to the beam isocenter based on the collected position information;
Correlating the objective output with parameters of the beam;
Including methods. A method of treating a patient target using ionizing radiation comprising:
Generating a beam of ionizing radiation and directing the beam to the target using a multi-leaf collimator;
Collecting position information of markers implanted at a position associated with the target within a patient while directing the beam to the beam isocenter;
Providing an objective output indicating the position of the target of the patient relative to the beam isocenter based on the collected position information and controlling the placement of a multi-leaf collimator based on the objective output; ,
Including methods. A method of treating a patient target using ionizing radiation comprising:
Generating a beam of ionizing radiation and directing the beam to the target;
(A) collecting position information of markers embedded at a position associated with the target within a patient while directing the beam to the beam isocenter; and (b) directing the beam to the beam isocenter; Positioning to provide an objective output indicating the position of the target relative to the beam isocenter based on the collected position information of the marker while aiming for at least 10 seconds without recalibrating the positioning system Steps to operate the system;
Including methods.

Images